1. Field of the Invention
The present invention relates to marine shore electrical power cord set. More particularly, it relates to securement collars for the plug ends of marine shore electrical power cord sets.
2. Description of the Related Art
Marine shore electrical power cord sets are well known. An example is the MARINECO electrical power connector manufactured by Marine Industries Company. Such cord sets typically have two or more plug ends which are intended to mate with cooperating marine electrical power inlet or receptacle on a boat or a shore power supply in order to supply electrical power to the boat. As such, they include high capacity electrical wiring, together with the necessary insulation.
Due to the stringent requirements for operation under difficult marine conditions, it is necessary to assure that the electrical connections are water tight and will not become inadvertently loosened, e.g., owing to movement of the boat. For this purpose, it has been known to provide securement collars which are typically in the form of a threaded ring but may also be rings having lugs for a bayonet connection, in order to secure the plug ends of the cord set to the mating connectors. For simplicity of description, the remainder of the description and the claims will refer to a threaded securement collar, which is to be interpreted as also including securement collars having lugs for bayonet type connections. Similarly, any further reference to screw threads is to be interpreted as including lugs for bayonet type connections.
For example, referring to FIGS. 1 and 2, which respectively show two plug ends of a conventional MARINECO power cord set, the power cord set and its plug ends 2 are covered by a heavy rubber waterproof insulation and have distal ends 4 of a circular section, which are sized and configured to fit into the inlet or receptacle connections of a boat or a shore power source. An elastic external rubber retention ring 6 is formed integrally with the insulation, and is spaced by an appropriate distance from the distal end 4 of the plug end 2.
The securement collar 8 is formed of a rigid material, e.g., a hard plastic, and has internal threads 10 designed to mate with external threads of the shore/boat connection, as well as a radially inwardly extending tapered shoulder 12. The inner diameter of the collar 8 is slightly larger than the outer diameter of the elastic retention ring 6, whereas the diameter of the inner lip 14 of the shoulder 12 is smaller than the outer diameter of the retention ring 6, so that the shoulder 12 and the retention ring 6 can cooperate to retain the collar 8 on the plug end 2. Accordingly, when the plug end 2 of the power connector is plugged into the cooperating inlet or receptacle of the boat or shore power supply, and the screw threads 10 are threaded with the cooperating screw threads of the boat or shore power supply inlet or receptacle, the radial shoulder 12 and retention ring 6 cooperate to assure a secure and waterproof connection.
On the other hand, there is no universal standard design for shore or boat power connections, and so the conventional securement collar 8 will not necessarily work with all shore or boat plug connections. The power cord set is therefore normally sold with the securement collar 8 dismounted from the plug end 2 thereof, and the securement collar 8 must be mounted to the plug end 2 when appropriate. This involves lubricating the plug end 2 and forcefully prying the tapered radial shoulder 12 over the retention ring 6, an operation which may be difficult to perform. Similarly, if the securement collar 8 is already mounted to the plug end 2, it must be pried off of the retention ring 6 when the power cord set is to be secured to a boat or shore power connector which is not compatible with the securement collar. Again, this requires forceful prying and is not easily done.